 	  max-obj (reduce #(max %1 (count (str %2))) 0 objects)]
       (with-str-out
 	"\n" 
-	(ensure-length "" max-obj " ") " |" (for [att attributes] [att " "]) "\n"
+	(ensure-length "" max-obj " ") " |" (for [att attributes] [(str att) " "]) "\n"
 	(ensure-length "" max-obj "-") "-+" (for [att attributes]
 					      (ensure-length "" (inc (count (str att))) "-")) "\n"
 	(for [obj objects]

(defn concepts [ctx]
  (set-of [ objs (object-derivation ctx objs) ]
	  [ objs (context-extends ctx) ]))

   :constructors { [ clojure.lang.PersistentHashSet clojure.lang.PersistentHashSet clojure.lang.IFn ] [] }
   :state state)
  (:use [clojure.contrib.str-utils :only (str-join)]
	clojure.set
	conexp.base
	conexp.util))

